[dpdk-dev] [PATCH v6 2/5] net/enetfec: add UIO support

[Apeksha Gupta <apeksha.gupta@nxp.com>]

Implemented the fec-uio driver in kernel. enetfec PMD uses
UIO interface to interact with "fec-uio" driver implemented in
kernel for PHY initialisation and for mapping the allocated memory
of register & BD from kernel to DPDK which gives access to
non-cacheable memory for BD.

Signed-off-by: Sachin Saxena <sachin.saxena@nxp.com>
Signed-off-by: Apeksha Gupta <apeksha.gupta@nxp.com>
---
 drivers/net/enetfec/enet_ethdev.c | 236 +++++++++++++++++++++++++
 drivers/net/enetfec/enet_ethdev.h |   2 +
 drivers/net/enetfec/enet_regs.h   | 106 ++++++++++++
 drivers/net/enetfec/enet_uio.c    | 278 ++++++++++++++++++++++++++++++
 drivers/net/enetfec/enet_uio.h    |  64 +++++++
 5 files changed, 686 insertions(+)
 create mode 100644 drivers/net/enetfec/enet_regs.h
 create mode 100644 drivers/net/enetfec/enet_uio.c
 create mode 100644 drivers/net/enetfec/enet_uio.h

diff --git a/drivers/net/enetfec/enet_ethdev.c b/drivers/net/enetfec/enet_ethdev.c
index 8a74fb5bf2..406a8db7f3 100644
--- a/drivers/net/enetfec/enet_ethdev.c
+++ b/drivers/net/enetfec/enet_ethdev.c
@@ -13,16 +13,221 @@
 #include <rte_bus_vdev.h>
 #include <rte_dev.h>
 #include <rte_ether.h>
+#include <rte_io.h>
 #include "enet_ethdev.h"
 #include "enet_pmd_logs.h"
+#include "enet_regs.h"
+#include "enet_uio.h"
 
 #define ENETFEC_NAME_PMD                net_enetfec
 #define ENETFEC_CDEV_INVALID_FD         -1
+#define BIT(nr)				(1u << (nr))
+
+/* FEC receive acceleration */
+#define ENETFEC_RACC_IPDIS		BIT(1)
+#define ENETFEC_RACC_PRODIS		BIT(2)
+#define ENETFEC_RACC_SHIFT16		BIT(7)
+#define ENETFEC_RACC_OPTIONS		(ENETFEC_RACC_IPDIS | \
+						ENETFEC_RACC_PRODIS)
+
+#define ENETFEC_PAUSE_FLAG_AUTONEG	0x1
+#define ENETFEC_PAUSE_FLAG_ENABLE	0x2
+
+/* Pause frame field and FIFO threshold */
+#define ENETFEC_FCE			BIT(5)
+#define ENETFEC_RSEM_V			0x84
+#define ENETFEC_RSFL_V			16
+#define ENETFEC_RAEM_V			0x8
+#define ENETFEC_RAFL_V			0x8
+#define ENETFEC_OPD_V			0xFFF0
+
+#define NUM_OF_QUEUES			6
+
+uint32_t e_cntl;
+
+/*
+ * This function is called to start or restart the ENETFEC during a link
+ * change, transmit timeout, or to reconfigure the ENETFEC. The network
+ * packet processing for this device must be stopped before this call.
+ */
+static void
+enetfec_restart(struct rte_eth_dev *dev)
+{
+	struct enetfec_private *fep = dev->data->dev_private;
+	uint32_t temp_mac[2];
+	uint32_t rcntl = OPT_FRAME_SIZE | 0x04;
+	uint32_t ecntl = ENETFEC_ETHEREN;
+
+	/* default mac address */
+	struct rte_ether_addr addr = {
+		.addr_bytes = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6} };
+	uint32_t val;
+
+	/*
+	 * enet-mac reset will reset mac address registers too,
+	 * so need to reconfigure it.
+	 */
+	memcpy(&temp_mac, addr.addr_bytes, ETH_ALEN);
+	rte_write32(rte_cpu_to_be_32(temp_mac[0]),
+		(uint8_t *)fep->hw_baseaddr_v + ENETFEC_PALR);
+	rte_write32(rte_cpu_to_be_32(temp_mac[1]),
+		(uint8_t *)fep->hw_baseaddr_v + ENETFEC_PAUR);
+
+	/* Clear any outstanding interrupt. */
+	writel(0xffffffff, (uint8_t *)fep->hw_baseaddr_v + ENETFEC_EIR);
+
+	/* Enable MII mode */
+	if (fep->full_duplex == FULL_DUPLEX) {
+		/* FD enable */
+		rte_write32(rte_cpu_to_le_32(0x04),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_TCR);
+	} else {
+	/* No Rcv on Xmit */
+		rcntl |= 0x02;
+		rte_write32(0, (uint8_t *)fep->hw_baseaddr_v + ENETFEC_TCR);
+	}
+
+	if (fep->quirks & QUIRK_RACC) {
+		val = rte_read32((uint8_t *)fep->hw_baseaddr_v + ENETFEC_RACC);
+		/* align IP header */
+		val |= ENETFEC_RACC_SHIFT16;
+		val &= ~ENETFEC_RACC_OPTIONS;
+		rte_write32(rte_cpu_to_le_32(val),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_RACC);
+		rte_write32(rte_cpu_to_le_32(PKT_MAX_BUF_SIZE),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_FRAME_TRL);
+	}
+
+	/*
+	 * The phy interface and speed need to get configured
+	 * differently on enet-mac.
+	 */
+	if (fep->quirks & QUIRK_HAS_ENETFEC_MAC) {
+		/* Enable flow control and length check */
+		rcntl |= 0x40000000 | 0x00000020;
+
+		/* RGMII, RMII or MII */
+		rcntl |= BIT(6);
+		ecntl |= BIT(5);
+	}
+
+	/* enable pause frame*/
+	if ((fep->flag_pause & ENETFEC_PAUSE_FLAG_ENABLE) ||
+		((fep->flag_pause & ENETFEC_PAUSE_FLAG_AUTONEG)
+		/*&& ndev->phydev && ndev->phydev->pause*/)) {
+		rcntl |= ENETFEC_FCE;
+
+		/* set FIFO threshold parameter to reduce overrun */
+		rte_write32(rte_cpu_to_le_32(ENETFEC_RSEM_V),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_R_FIFO_SEM);
+		rte_write32(rte_cpu_to_le_32(ENETFEC_RSFL_V),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_R_FIFO_SFL);
+		rte_write32(rte_cpu_to_le_32(ENETFEC_RAEM_V),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_R_FIFO_AEM);
+		rte_write32(rte_cpu_to_le_32(ENETFEC_RAFL_V),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_R_FIFO_AFL);
+
+		/* OPD */
+		rte_write32(rte_cpu_to_le_32(ENETFEC_OPD_V),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_OPD);
+	} else {
+		rcntl &= ~ENETFEC_FCE;
+	}
+
+	rte_write32(rte_cpu_to_le_32(rcntl),
+		(uint8_t *)fep->hw_baseaddr_v + ENETFEC_RCR);
+
+	rte_write32(0, (uint8_t *)fep->hw_baseaddr_v + ENETFEC_IAUR);
+	rte_write32(0, (uint8_t *)fep->hw_baseaddr_v + ENETFEC_IALR);
+
+	if (fep->quirks & QUIRK_HAS_ENETFEC_MAC) {
+		/* enable ENETFEC endian swap */
+		ecntl |= (1 << 8);
+		/* enable ENETFEC store and forward mode */
+		rte_write32(rte_cpu_to_le_32(1 << 8),
+			(uint8_t *)fep->hw_baseaddr_v + ENETFEC_TFWR);
+	}
+	if (fep->bufdesc_ex)
+		ecntl |= (1 << 4);
+	if (fep->quirks & QUIRK_SUPPORT_DELAYED_CLKS &&
+		fep->rgmii_txc_delay)
+		ecntl |= ENETFEC_TXC_DLY;
+	if (fep->quirks & QUIRK_SUPPORT_DELAYED_CLKS &&
+		fep->rgmii_rxc_delay)
+		ecntl |= ENETFEC_RXC_DLY;
+	/* Enable the MIB statistic event counters */
+	rte_write32(0, (uint8_t *)fep->hw_baseaddr_v + ENETFEC_MIBC);
+
+	ecntl |= 0x70000000;
+	e_cntl = ecntl;
+	/* And last, enable the transmit and receive processing */
+	rte_write32(rte_cpu_to_le_32(ecntl),
+		(uint8_t *)fep->hw_baseaddr_v + ENETFEC_ECR);
+	rte_delay_us(10);
+}
+
+static int
+enetfec_eth_configure(__rte_unused struct rte_eth_dev *dev)
+{
+	if (dev->data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_KEEP_CRC)
+		ENETFEC_PMD_ERR("PMD does not support KEEP_CRC offload");
+
+	return 0;
+}
+
+static int
+enetfec_eth_start(struct rte_eth_dev *dev)
+{
+	enetfec_restart(dev);
+
+	return 0;
+}
+/* ENETFEC enable function.
+ * @param[in] base      ENETFEC base address
+ */
+void
+enetfec_enable(void *base)
+{
+	rte_write32(rte_read32((uint8_t *)base + ENETFEC_ECR) | e_cntl,
+					(uint8_t *)base + ENETFEC_ECR);
+}
+
+/* ENETFEC disable function.
+ * @param[in] base      ENETFEC base address
+ */
+void
+enetfec_disable(void *base)
+{
+	rte_write32(rte_read32((uint8_t *)base + ENETFEC_ECR) & ~e_cntl,
+					(uint8_t *)base + ENETFEC_ECR);
+}
+
+static int
+enetfec_eth_stop(__rte_unused struct rte_eth_dev *dev)
+{
+	struct enetfec_private *fep = dev->data->dev_private;
+
+	dev->data->dev_started = 0;
+	enetfec_disable(fep->hw_baseaddr_v);
+
+	return 0;
+}
+
+static const struct eth_dev_ops enetfec_ops = {
+	.dev_configure          = enetfec_eth_configure,
+	.dev_start              = enetfec_eth_start,
+	.dev_stop               = enetfec_eth_stop
+};
 
 static int
 enetfec_eth_init(struct rte_eth_dev *dev)
 {
+	struct enetfec_private *fep = dev->data->dev_private;
+
+	fep->full_duplex = FULL_DUPLEX;
+	dev->dev_ops = &enetfec_ops;
 	rte_eth_dev_probing_finish(dev);
+
 	return 0;
 }
 
@@ -33,6 +238,8 @@ pmd_enetfec_probe(struct rte_vdev_device *vdev)
 	struct enetfec_private *fep;
 	const char *name;
 	int rc;
+	int i;
+	unsigned int bdsize;
 
 	name = rte_vdev_device_name(vdev);
 	if (name == NULL)
@@ -46,6 +253,35 @@ pmd_enetfec_probe(struct rte_vdev_device *vdev)
 	/* setup board info structure */
 	fep = dev->data->dev_private;
 	fep->dev = dev;
+
+	fep->max_rx_queues = ENETFEC_MAX_Q;
+	fep->max_tx_queues = ENETFEC_MAX_Q;
+	fep->quirks = QUIRK_HAS_ENETFEC_MAC | QUIRK_GBIT
+		| QUIRK_RACC;
+
+	rc = enetfec_configure();
+	if (rc != 0)
+		return -ENOMEM;
+	rc = config_enetfec_uio(fep);
+	if (rc != 0)
+		return -ENOMEM;
+
+	/* Get the BD size for distributing among six queues */
+	bdsize = (fep->bd_size) / NUM_OF_QUEUES;
+
+	for (i = 0; i < fep->max_tx_queues; i++) {
+		fep->dma_baseaddr_t[i] = fep->bd_addr_v;
+		fep->bd_addr_p_t[i] = fep->bd_addr_p;
+		fep->bd_addr_v = (uint8_t *)fep->bd_addr_v + bdsize;
+		fep->bd_addr_p = fep->bd_addr_p + bdsize;
+	}
+	for (i = 0; i < fep->max_rx_queues; i++) {
+		fep->dma_baseaddr_r[i] = fep->bd_addr_v;
+		fep->bd_addr_p_r[i] = fep->bd_addr_p;
+		fep->bd_addr_v = (uint8_t *)fep->bd_addr_v + bdsize;
+		fep->bd_addr_p = fep->bd_addr_p + bdsize;
+	}
+
 	rc = enetfec_eth_init(dev);
 	if (rc)
 		goto failed_init;
diff --git a/drivers/net/enetfec/enet_ethdev.h b/drivers/net/enetfec/enet_ethdev.h
index c674dfc782..312e0424e5 100644
--- a/drivers/net/enetfec/enet_ethdev.h
+++ b/drivers/net/enetfec/enet_ethdev.h
@@ -175,5 +175,7 @@ struct bufdesc *enet_get_nextdesc(struct bufdesc *bdp,
 		struct bufdesc_prop *bd);
 int enet_new_rxbdp(struct enetfec_private *fep, struct bufdesc *bdp,
 		struct rte_mbuf *mbuf);
+void enetfec_enable(void *base);
+void enetfec_disable(void *base);
 
 #endif /*__ENETFEC_ETHDEV_H__*/
diff --git a/drivers/net/enetfec/enet_regs.h b/drivers/net/enetfec/enet_regs.h
new file mode 100644
index 0000000000..5415ed77ea
--- /dev/null
+++ b/drivers/net/enetfec/enet_regs.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2020 NXP
+ */
+
+#ifndef __ENETFEC_REGS_H
+#define __ENETFEC_REGS_H
+
+/* Ethernet receive use control and status of buffer descriptor
+ */
+#define RX_BD_TR	((ushort)0x0001) /* Truncated */
+#define RX_BD_OV	((ushort)0x0002) /* Over-run */
+#define RX_BD_CR	((ushort)0x0004) /* CRC or Frame error */
+#define RX_BD_SH	((ushort)0x0008) /* Reserved */
+#define RX_BD_NO	((ushort)0x0010) /* Rcvd non-octet aligned frame */
+#define RX_BD_LG	((ushort)0x0020) /* Rcvd frame length voilation */
+#define RX_BD_FIRST	((ushort)0x0400) /* Reserved */
+#define RX_BD_LAST	((ushort)0x0800) /* last buffer in the frame */
+#define RX_BD_INT	0x00800000
+#define RX_BD_ICE	0x00000020
+#define RX_BD_PCR	0x00000010
+
+/*
+ * 0 The next BD in consecutive location
+ * 1 The next BD in ENETFECn_RDSR.
+ */
+#define RX_BD_WRAP	((ushort)0x2000)
+#define RX_BD_EMPTY	((ushort)0x8000) /* BD is empty */
+#define RX_BD_STATS	((ushort)0x013f) /* All buffer descriptor status bits */
+
+/* Ethernet transmit use control and status of buffer descriptor */
+#define TX_BD_TC	((ushort)0x0400) /* Transmit CRC */
+#define TX_BD_LAST	((ushort)0x0800) /* Last in frame */
+#define TX_BD_READY	((ushort)0x8000) /* Data is ready */
+#define TX_BD_STATS	((ushort)0x0fff) /* All buffer descriptor status bits */
+#define TX_BD_WRAP	((ushort)0x2000)
+
+/* Ethernet transmit use control and status of enhanced buffer descriptor */
+#define TX_BD_IINS		0x08000000
+#define TX_BD_PINS		0x10000000
+
+#define ENETFEC_RD_START(X)	(((X) == 1) ? ENETFEC_RD_START_1 : \
+				(((X) == 2) ? \
+				   ENETFEC_RD_START_2 : ENETFEC_RD_START_0))
+#define ENETFEC_TD_START(X)	(((X) == 1) ? ENETFEC_TD_START_1 : \
+				(((X) == 2) ? \
+				   ENETFEC_TD_START_2 : ENETFEC_TD_START_0))
+#define ENETFEC_MRB_SIZE(X)	(((X) == 1) ? ENETFEC_MRB_SIZE_1 : \
+				(((X) == 2) ? \
+				   ENETFEC_MRB_SIZE_2 : ENETFEC_MRB_SIZE_0))
+
+#define ENETFEC_ETHEREN		((uint)0x00000002)
+#define ENETFEC_TXC_DLY		((uint)0x00010000)
+#define ENETFEC_RXC_DLY		((uint)0x00020000)
+
+/* ENETFEC MAC is in controller */
+#define QUIRK_HAS_ENETFEC_MAC	(1 << 0)
+/* GBIT supported in controller */
+#define QUIRK_GBIT		(1 << 3)
+/* RACC register supported by controller */
+#define QUIRK_RACC		(1 << 12)
+/* i.MX8 ENETFEC IP version added the feature to generate the delayed TXC or
+ * RXC. For its implementation, ENETFEC uses synchronized clocks (250MHz) for
+ * generating delay of 2ns.
+ */
+#define QUIRK_SUPPORT_DELAYED_CLKS	(1 << 18)
+
+#define ENETFEC_EIR	0x004 /* Interrupt event register */
+#define ENETFEC_EIMR	0x008 /* Interrupt mask register */
+#define ENETFEC_RDAR_0	0x010 /* Receive descriptor active register ring0 */
+#define ENETFEC_TDAR_0	0x014 /* Transmit descriptor active register ring0 */
+#define ENETFEC_ECR	0x024 /* Ethernet control register */
+#define ENETFEC_MSCR	0x044 /* MII speed control register */
+#define ENETFEC_MIBC	0x064 /* MIB control and status register */
+#define ENETFEC_RCR	0x084 /* Receive control register */
+#define ENETFEC_TCR	0x0c4 /* Transmit Control register */
+#define ENETFEC_PALR	0x0e4 /* MAC address low 32 bits */
+#define ENETFEC_PAUR	0x0e8 /* MAC address high 16 bits */
+#define ENETFEC_OPD	0x0ec /* Opcode/Pause duration register */
+#define ENETFEC_IAUR	0x118 /* hash table 32 bits high */
+#define ENETFEC_IALR	0x11c /* hash table 32 bits low */
+#define ENETFEC_GAUR	0x120 /* grp hash table 32 bits high */
+#define ENETFEC_GALR	0x124 /* grp hash table 32 bits low */
+#define ENETFEC_TFWR	0x144 /* transmit FIFO water_mark */
+#define ENETFEC_RACC	0x1c4 /* Receive Accelerator function configuration*/
+#define ENETFEC_DMA1CFG	0x1d8 /* DMA class based configuration ring1 */
+#define ENETFEC_DMA2CFG	0x1dc /* DMA class based Configuration ring2 */
+#define ENETFEC_RDAR_1	0x1e0 /* Rx descriptor active register ring1 */
+#define ENETFEC_TDAR_1	0x1e4 /* Tx descriptor active register ring1 */
+#define ENETFEC_RDAR_2	0x1e8 /* Rx descriptor active register ring2 */
+#define ENETFEC_TDAR_2	0x1ec /* Tx descriptor active register ring2 */
+#define ENETFEC_RD_START_1	0x160 /* Receive descriptor ring1 start reg */
+#define ENETFEC_TD_START_1	0x164 /* Transmit descriptor ring1 start reg */
+#define ENETFEC_MRB_SIZE_1	0x168 /* Max receive buffer size reg ring1 */
+#define ENETFEC_RD_START_2	0x16c /* Receive descriptor ring2 start reg */
+#define ENETFEC_TD_START_2	0x170 /* Transmit descriptor ring2 start reg */
+#define ENETFEC_MRB_SIZE_2	0x174 /* Max receive buffer size reg ring2 */
+#define ENETFEC_RD_START_0	0x180 /* Receive descriptor ring0 start reg */
+#define ENETFEC_TD_START_0	0x184 /* Transmit descriptor ring0 start reg */
+#define ENETFEC_MRB_SIZE_0	0x188 /* Max receive buffer size reg ring0*/
+#define ENETFEC_R_FIFO_SFL	0x190 /* Rx FIFO full threshold */
+#define ENETFEC_R_FIFO_SEM	0x194 /* Rx FIFO empty threshold */
+#define ENETFEC_R_FIFO_AEM	0x198 /* Rx FIFO almost empty threshold */
+#define ENETFEC_R_FIFO_AFL	0x19c /* Rx FIFO almost full threshold */
+#define ENETFEC_FRAME_TRL	0x1b0 /* Frame truncation length */
+
+#endif /*__ENETFEC_REGS_H */
diff --git a/drivers/net/enetfec/enet_uio.c b/drivers/net/enetfec/enet_uio.c
new file mode 100644
index 0000000000..c939b4736b
--- /dev/null
+++ b/drivers/net/enetfec/enet_uio.c
@@ -0,0 +1,278 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2021 NXP
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <rte_common.h>
+#include <rte_malloc.h>
+#include "enet_pmd_logs.h"
+#include "enet_uio.h"
+
+static struct uio_job enetfec_uio_job;
+static int enetfec_count;
+
+/** @brief Checks if a file name contains a certain substring.
+ * This function assumes a filename format of: [text][number].
+ * @param [in]  filename    File name
+ * @param [in]  match       String to match in file name
+ *
+ * @retval true if file name matches the criteria
+ * @retval false if file name does not match the criteria
+ */
+static bool
+file_name_match_extract(const char filename[], const char match[])
+{
+	char *substr = NULL;
+
+	substr = strstr(filename, match);
+	if (substr == NULL)
+		return false;
+
+	return true;
+}
+
+/*
+ * @brief Reads first line from a file.
+ * Composes file name as: root/subdir/filename
+ *
+ * @param [in]  root     Root path
+ * @param [in]  subdir   Subdirectory name
+ * @param [in]  filename File name
+ * @param [out] line     The first line read from file.
+ *
+ * @retval 0 for success
+ * @retval other value for error
+ */
+static int
+file_read_first_line(const char root[], const char subdir[],
+			const char filename[], char *line)
+{
+	char absolute_file_name[FEC_UIO_MAX_ATTR_FILE_NAME];
+	int fd = 0, ret = 0;
+
+	/*compose the file name: root/subdir/filename */
+	memset(absolute_file_name, 0, sizeof(absolute_file_name));
+	snprintf(absolute_file_name, FEC_UIO_MAX_ATTR_FILE_NAME,
+		"%s/%s/%s", root, subdir, filename);
+
+	fd = open(absolute_file_name, O_RDONLY);
+	if (fd <= 0)
+		ENETFEC_PMD_ERR("Error opening file %s", absolute_file_name);
+
+	/* read UIO device name from first line in file */
+	ret = read(fd, line, FEC_UIO_MAX_DEVICE_FILE_NAME_LENGTH);
+	if (ret <= 0) {
+		ENETFEC_PMD_ERR("Error reading file %s", absolute_file_name);
+		return ret;
+	}
+	close(fd);
+
+	/* NULL-ify string */
+	line[ret] = '\0';
+
+	return 0;
+}
+
+/*
+ * @brief Maps rx-tx bd range assigned for a bd ring.
+ *
+ * @param [in] uio_device_fd    UIO device file descriptor
+ * @param [in] uio_device_id    UIO device id
+ * @param [in] uio_map_id       UIO allows maximum 5 different mapping for
+				each device. Maps start with id 0.
+ * @param [out] map_size        Map size.
+ * @param [out] map_addr	Map physical address
+ *
+ * @retval  NULL if failed to map registers
+ * @retval  Virtual address for mapped register address range
+ */
+static void *
+uio_map_mem(int uio_device_fd, int uio_device_id,
+		int uio_map_id, int *map_size, uint64_t *map_addr)
+{
+	void *mapped_address = NULL;
+	unsigned int uio_map_size = 0;
+	unsigned int uio_map_p_addr = 0;
+	char uio_sys_root[FEC_UIO_MAX_ATTR_FILE_NAME];
+	char uio_sys_map_subdir[FEC_UIO_MAX_ATTR_FILE_NAME];
+	char uio_map_size_str[FEC_UIO_MAX_DEVICE_FILE_NAME_LENGTH + 1];
+	char uio_map_p_addr_str[32];
+	int ret = 0;
+
+	/* compose the file name: root/subdir/filename */
+	memset(uio_sys_root, 0, sizeof(uio_sys_root));
+	memset(uio_sys_map_subdir, 0, sizeof(uio_sys_map_subdir));
+	memset(uio_map_size_str, 0, sizeof(uio_map_size_str));
+	memset(uio_map_p_addr_str, 0, sizeof(uio_map_p_addr_str));
+
+	/* Compose string: /sys/class/uio/uioX */
+	snprintf(uio_sys_root, sizeof(uio_sys_root), "%s/%s%d",
+			FEC_UIO_DEVICE_SYS_ATTR_PATH, "uio", uio_device_id);
+	/* Compose string: maps/mapY */
+	snprintf(uio_sys_map_subdir, sizeof(uio_sys_map_subdir), "%s%d",
+			FEC_UIO_DEVICE_SYS_MAP_ATTR, uio_map_id);
+
+	/* Read first (and only) line from file
+	 * /sys/class/uio/uioX/maps/mapY/size
+	 */
+	ret = file_read_first_line(uio_sys_root, uio_sys_map_subdir,
+				"size", uio_map_size_str);
+	if (ret < 0) {
+		ENETFEC_PMD_ERR("file_read_first_line() failed");
+		return NULL;
+	}
+	ret = file_read_first_line(uio_sys_root, uio_sys_map_subdir,
+				"addr", uio_map_p_addr_str);
+	if (ret < 0) {
+		ENETFEC_PMD_ERR("file_read_first_line() failed");
+		return NULL;
+	}
+	/* Read mapping size and physical address expressed in hexa(base 16) */
+	uio_map_size = strtol(uio_map_size_str, NULL, 16);
+	uio_map_p_addr = strtol(uio_map_p_addr_str, NULL, 16);
+
+	if (uio_map_id == 0) {
+		/* Map the register address in user space when map_id is 0 */
+		mapped_address = mmap(0 /*dynamically choose virtual address */,
+				uio_map_size, PROT_READ | PROT_WRITE,
+				MAP_SHARED, uio_device_fd, 0);
+	} else {
+		/* Map the BD memory in user space */
+		mapped_address = mmap(NULL, uio_map_size,
+				PROT_READ | PROT_WRITE,
+				MAP_SHARED, uio_device_fd, (1 * MAP_PAGE_SIZE));
+	}
+
+	if (mapped_address == MAP_FAILED) {
+		ENETFEC_PMD_ERR("Failed to map! errno = %d uio job fd = %d,"
+			"uio device id = %d, uio map id = %d", errno,
+			uio_device_fd, uio_device_id, uio_map_id);
+		return NULL;
+	}
+
+	/* Save the map size to use it later on for munmap-ing */
+	*map_size = uio_map_size;
+	*map_addr = uio_map_p_addr;
+	ENETFEC_PMD_INFO("UIO dev[%d] mapped region [id =%d] size 0x%x at %p",
+		uio_device_id, uio_map_id, uio_map_size, mapped_address);
+
+	return mapped_address;
+}
+
+int
+config_enetfec_uio(struct enetfec_private *fep)
+{
+	char uio_device_file_name[32];
+	struct uio_job *uio_job = NULL;
+
+	/* Mapping is done only one time */
+	if (enetfec_count > 0) {
+		ENETFEC_PMD_INFO("Mapped!\n");
+		return 0;
+	}
+
+	uio_job = &enetfec_uio_job;
+
+	/* Find UIO device created by ENETFEC-UIO kernel driver */
+	memset(uio_device_file_name, 0, sizeof(uio_device_file_name));
+	snprintf(uio_device_file_name, sizeof(uio_device_file_name), "%s%d",
+			FEC_UIO_DEVICE_FILE_NAME, uio_job->uio_minor_number);
+
+	/* Open device file */
+	uio_job->uio_fd = open(uio_device_file_name, O_RDWR);
+	if (uio_job->uio_fd < 0) {
+		ENETFEC_PMD_WARN("Unable to open ENETFEC_UIO file\n");
+		return -1;
+	}
+
+	ENETFEC_PMD_INFO("US_UIO: Open device(%s) file with uio_fd = %d",
+			uio_device_file_name, uio_job->uio_fd);
+
+	fep->hw_baseaddr_v = uio_map_mem(uio_job->uio_fd,
+		uio_job->uio_minor_number, FEC_UIO_REG_MAP_ID,
+		&uio_job->map_size, &uio_job->map_addr);
+	if (fep->hw_baseaddr_v == NULL)
+		return -ENOMEM;
+	fep->hw_baseaddr_p = uio_job->map_addr;
+	fep->reg_size = uio_job->map_size;
+
+	fep->bd_addr_v = uio_map_mem(uio_job->uio_fd,
+		uio_job->uio_minor_number, FEC_UIO_BD_MAP_ID,
+		&uio_job->map_size, &uio_job->map_addr);
+	if (fep->hw_baseaddr_v == NULL)
+		return -ENOMEM;
+	fep->bd_addr_p = uio_job->map_addr;
+	fep->bd_size = uio_job->map_size;
+
+	enetfec_count++;
+
+	return 0;
+}
+
+int
+enetfec_configure(void)
+{
+	char uio_name[32];
+	int uio_minor_number = -1;
+	int ret;
+	DIR *d = NULL;
+	struct dirent *dir;
+
+	d = opendir(FEC_UIO_DEVICE_SYS_ATTR_PATH);
+	if (d == NULL) {
+		ENETFEC_PMD_ERR("\nError opening directory '%s': %s\n",
+			FEC_UIO_DEVICE_SYS_ATTR_PATH, strerror(errno));
+		return -1;
+	}
+
+	/* Iterate through all subdirs */
+	while ((dir = readdir(d)) != NULL) {
+		if (!strncmp(dir->d_name, ".", 1) ||
+				!strncmp(dir->d_name, "..", 2))
+			continue;
+
+		if (file_name_match_extract(dir->d_name, "uio")) {
+			/*
+			 * As substring <uio> was found in <d_name>
+			 * read number following <uio> substring in <d_name>
+			 */
+			ret = sscanf(dir->d_name + strlen("uio"), "%d",
+							&uio_minor_number);
+			if (ret < 0)
+				ENETFEC_PMD_ERR("Error: not find minor number\n");
+			/*
+			 * Open file uioX/name and read first line which
+			 * contains the name for the device. Based on the
+			 * name check if this UIO device is for enetfec.
+			 */
+			memset(uio_name, 0, sizeof(uio_name));
+			ret = file_read_first_line(FEC_UIO_DEVICE_SYS_ATTR_PATH,
+					dir->d_name, "name", uio_name);
+			if (ret != 0) {
+				ENETFEC_PMD_INFO("file_read_first_line failed\n");
+				closedir(d);
+				return -1;
+			}
+
+			if (file_name_match_extract(uio_name,
+						FEC_UIO_DEVICE_NAME)) {
+				enetfec_uio_job.uio_minor_number =
+							uio_minor_number;
+				ENETFEC_PMD_INFO("enetfec device uio name: %s",
+						 uio_name);
+			}
+		}
+	}
+	closedir(d);
+	return 0;
+}
diff --git a/drivers/net/enetfec/enet_uio.h b/drivers/net/enetfec/enet_uio.h
new file mode 100644
index 0000000000..4a031d3f46
--- /dev/null
+++ b/drivers/net/enetfec/enet_uio.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2021 NXP
+ */
+
+#include "enet_ethdev.h"
+
+/* Prefix path to sysfs directory where UIO device attributes are exported.
+ * Path for UIO device X is /sys/class/uio/uioX
+ */
+#define FEC_UIO_DEVICE_SYS_ATTR_PATH	"/sys/class/uio"
+
+/* Subfolder in sysfs where mapping attributes are exported
+ * for each UIO device. Path for mapping Y for device X is:
+ * /sys/class/uio/uioX/maps/mapY
+ */
+#define FEC_UIO_DEVICE_SYS_MAP_ATTR	"maps/map"
+
+/* Name of UIO device file prefix. Each UIO device will have a device file
+ * /dev/uioX, where X is the minor device number.
+ */
+#define FEC_UIO_DEVICE_FILE_NAME	"/dev/uio"
+/*
+ * Name of UIO device. User space FEC will have a corresponding
+ * UIO device.
+ * Maximum length is #FEC_UIO_MAX_DEVICE_NAME_LENGTH.
+ *
+ * @note  Must be kept in sync with FEC kernel driver
+ * define #FEC_UIO_DEVICE_NAME !
+ */
+#define FEC_UIO_DEVICE_NAME     "imx-fec-uio"
+
+/* Maximum length for the name of an UIO device file.
+ * Device file name format is: /dev/uioX.
+ */
+#define FEC_UIO_MAX_DEVICE_FILE_NAME_LENGTH	30
+
+/* Maximum length for the name of an attribute file for an UIO device.
+ * Attribute files are exported in sysfs and have the name formatted as:
+ * /sys/class/uio/uioX/<attribute_file_name>
+ */
+#define FEC_UIO_MAX_ATTR_FILE_NAME	100
+
+/* The id for the mapping used to export ENETFEC registers and BD memory to
+ * user space through UIO device.
+ */
+#define FEC_UIO_REG_MAP_ID		0
+#define FEC_UIO_BD_MAP_ID		1
+
+#define MAP_PAGE_SIZE			4096
+
+struct uio_job {
+	uint32_t fec_id;
+	int uio_fd;
+	void *bd_start_addr;
+	void *register_base_addr;
+	int map_size;
+	uint64_t map_addr;
+	int uio_minor_number;
+};
+
+int enetfec_configure(void);
+int config_enetfec_uio(struct enetfec_private *fep);
+void enetfec_uio_init(void);
+void enetfec_cleanup(void);
-- 
2.17.1